Ski and method of manufacturing the ski

ABSTRACT

A method of manufacturing a ski in which bonding portions join non-metal side members ( 20 ) and a metal sheet ( 18 ) to form a cap preform section. The cap preform section is pressed downward against the top surface of a core ( 14 ) and heat is applied to bond the cap preform section to the core ( 14 ). The bonding portions include bonding strips ( 22 ) formed of a thermoplastic material that becomes adhesive when subjected to pressure and heat at a sufficiently high temperature.

RELATED REFERENCES

This application claims priority benefit of U.S. Provisional Ser. No.60/238,725 filed Oct. 6, 2000.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The present invention relates to a snow ski, and more particularly to acomposite snow ski and a method of making the same. More particularly,this relates to a composite snow ski having a desired balance of designcharacteristics, and also an improved manufacturing process for makingthe ski.

b) Background Art

Various materials can be used in the manufacture of snow skis, andvarious designs have been proposed, which incorporate metal componentsas part of the structure of the ski, and in some cases using the metalto form some of the primary components of the ski structure. One suchdesign that has become commercially successful is disclosed in U.S. Pat.No. 4,858,945 (Kashiwa). In that particular design, the ski has a topmetal cap having a top horizontal portion and two downwardly extendingside portions forming at the outside side surfaces of the ski. Inaddition, there is a lower metal sheet above the running surface andbelow the wood core of the ski. This design has been demonstrated toprovide a certain number of advantages which are disclosed in the textof the U.S. patent. Among these is that there is improved torsionalresistance, desired weight distribution, also a desirable flexuralcharacteristics, and others.

In addition to this, there is shown in the prior art various proposeddesigns incorporating metal components one way or another, and a searchof the patent literature discloses a number of these.

U.S. Pat. No. 5,292,148 (Abondance et al.) shows a ski with an uppersurface 3, which is secured to side elements 8.

U.S. Pat. No. 5,280,943 (Comier) shows a ski, the various layers ofwhich are shown in FIG. 21. Layers 101, 102, and 103 may be formed ofmetal according to column 6, lines 26+.

U.S. Pat. No. 5,251,924 (Nussbaumer) shows a ski that is formed in atrough like mold 9, and cover 10. There is a metal upper cover layer 4,and a coated lower layer 5. The components appear to be united withresin like elements in the mold.

U.S. Pat. No. 4,781,395 (Fischer) shows a ski that is formed in a troughlike mold 9, and cover 10. There is a metal upper cover layer 4, and acoated lower layer 5. The components appear to be united with resin likeelements in the mold.

U.S. Pat. No. 4,731,038 (Hancock et al.) shows a mold 70, and cover 82,in which material including deck element 3, an inner plate 4, which maybe of aluminum are placed with other parts.

U.S. Pat. No. 4,671,529 (LeGrand et al.) shows a ski in which there arebearing layers 3 and 4 that are formed of aluminum.

U.S. Pat. No. 4,655,473 (Muller et al.) shows the fabrication of a skiin which parts not mentioned in column 3, lines 17 to 40, may be ofsteel or other materials.

U.S. Pat. No. 4,382,610 (Arnsteiner) shows a ski in which layers 2 and 6are formed of aluminum.

U.S. Pat. No. 4,233,098 (Urbain) shows a ski in which sheet metal layers9 and 12 are secured to a resin core 3. The sheet metal may be temperedcarbon steel according to claim 8.

U.S. Pat. No. 3,790,184 (Bandrowski) indicates in column 2, line a9,that casing 19 may be of metal or other materials.

U.S. Pat. No. 3,762,734 (Vogel) shows a ski in which the shell elements2 and 3 may be formed of steel, to which resin materials are secured.

U.S. Pat. No. 3,733,380 (Ishida) shows a ski that is formed of resinmolded around reinforcing elements 4 and 5. Reinforcing element 4includes metal layer 4c, as well as other materials.

U.S. Pat. No. 3,612,556 (Seawell) shows a ski in which there are sheetaluminum elements 8 and 9.

U.S. Pat. No. 3,416,810 (Kennedy) shows a ski in which element 20 andlegs 28 and 36 are formed of metal.

U.S. Pat. No. 3,272,522 (Kennedy) shows various configurations of a skiin which metal may be used as either an internal element or as a casing.The metallic elements are shown such as base 22, and associated sidewalls 24, there is a running surface such as 106 on the bottom. Otherembodiments are shown with internal metallic structures.

U.S. Pat. No. 3,145,998 (Holmberg et al.) shows structures of alaminated ski in which the embodiment shown in FIG. 5 includes uppersheet steel element 31, which is secured to aluminum sheet 29, andcovered with a layer of resin. There is a lower steel sheet 37, which issecured to aluminum sheet 35 on one side and covered on the outersurface with running element 45, also of resin.

U.S. Pat. No. 2,851,277 (Holmberg et al.) shows a ski with a core ofwood or wood compositions, and provided with sheet steel elements 31 and36 which are bonded to aluminum sheets.

SUMMARY OF THE INVENTION

The ski design of the present invention lends itself to efficient, costeffective and reliable manufacturing techniques, while providing thedesired balance of the functional and structural characteristics of theend product, and also the ability to provide desired aesthetic features(i.e. cosmetics).

The present invention comprises a design of a ski where metal (in thepreferred form steel) is used as a structural component or components,and in the preferred form where the ski has a metal structural sheetexposed at the top of the ski, combined with substantially non-metalside wall structural components which can, for example, be made of aplastic or fiber reinforced plastic composites. These are combined insuch a way as to form a desired balance of functional characteristics ofthe ski, and enable desirable cosmetics in the ski. In addition, thepresent invention comprises a manufacturing process which also has adesired balance of advantageous features, and which is uniquely adaptedto be used to make the type of ski described herein.

The ski which is manufactured by the past method of the presentinvention has a front to rear longitudinal axis, front and rear endportions, upper and lower surface portions, and side portions. Further,the ski comprises a main longitudinally extending body portioncomprising main body components of the ski and a longitudinallyextending cap portion at the upper and side surface portions of the ski.

The method comprises first making a cap preform section having a middlecap preform portion and side cap preform portions. The cap preformsection comprises:

-   -   i. an elongate metal sheet which is predominantly metal and has        upper and lower surfaces and side edge portions;    -   ii. two predominantly non-metal side members having upper and        lower surfaces and inner and outer edge portions, with the inner        edge portions being adjacent o the side edge portions of the        metal sheet at juncture locations;    -   iii. two bonding portions, each being located at a related one        of the juncture locations and joining a related one of the side        members to an adjacent side portion of the metal sheet.

Preform main body components that correspond to the main body componentsof the ski are positioned at a molding location as a main body preformassembly, with upper, lower and side surfaces and lower side edges.

The cap preform section is positioned over the main body preformassembly so that the metal sheet is located over the upper surface ofthe main body preform assembly. Then the middle portion of the cappreform section is pressed downwardly against the top surface of themain body preform assembly and the cap preform section has its sideportions pressed against the side surfaces of the main body preformassembly to form a bonding assembly. Heat is applied to cause the cappreform section of the main body preform assembly to come bonded in to aski structure.

In the preferred form an upper mold section is pressed downwardly topress the cap preform assembly downwardly against the main body preformassembly. In the bonding assembly outer edge portions of the cap preformsection extend outwardly beneath lower edge portions of the upper moldsection to form edge seals to contain liquid material in the main bodypreform assembly.

In a preferred form, there is a lower metal sheet which is predominantlymade of metal, and this is a component of the main body preformassembly. The main body preform assembly further comprises lower metalside edge members. In one arrangement, in merely extending flanges ofthe edge members have inner edge surfaces which are positioned adjacentto outer edge surfaces of the lower metal sheet. In anotherconfiguration, outer edge portions of the metal sheet are in overlappingrelationship with the flange portions.

Also, in the manufacturing process, outer edge portions of the cappreform assembly extend beyond lower side edge locations of the skiwhich is formed, and the method further comprises trimming back theouter edge portions of the cap preform assembly to form the ski.

In one arrangement, each of the bonding portions of the cap preformassembly comprises an end edge portion of related one of the sidemembers, and the side members are made of a thermoplastic material, andan adjacent edge portion of the metal sheet is pressed against the edgeportion of its related side member so as to form a bond between eachside member and the metal sheet.

In another currently preferred configuration, each of the two bondingportions comprises a bonding strip having an upper bonding surface. Thecap preform section is made by providing a cap preform assemblycomprising the metal sheet, the side members, and the bonding strip inoverlapping relationship and applying heat to bond the bonding strips tothe metal sheet and the side members to form the cap preform section.Desirably each of the bonding strips is made of a thermoplasticmaterial, and the bonding assembly is subjected to pressure and heat ata sufficiently high temperature to cause each bonding strip to becomeadhesive, and upon cooling forms a bond with the adjacent side memberand the metal sheet.

Also in a preferred form, the metal sheet and the two side members meetin edge to edge abutting relationship, and each of the thermoplasticbonding strips is heated to a sufficiently high level to create bonding,with each thermoplastic strip having a sufficiently high viscosity atthe bonding temperature so that leakage does not occur through a jointformed by the metal sheet and the adjacent side member.

In one embodiment, the bonding strip extends only part way downwardlyadjacent to an upper portion of its related side member. In anotherarrangement, each bonding strip extends downwardly along the sidesurface portions of its related side member to its related lower sideedge portion of the main body preform assembly.

One preferred form of the bonding strip is to have an outer surfaceportion having a material which readily bonds to metal material formingthe upper metal sheet and also to plastic material forming its relatedside member, and an inner surface material particularly adapted to aresin system which is incorporated in a main body preform assembly.

In one configuration, the metal sheet has two side edge surfaces, eachof which is in abutting relationship against an adjacent side portion ofthe side member. In one arrangement the upper metal sheet is entirelyflat and is positioned at an upper top surface of the ski. In anotherarrangement the upper metal sheet has side edge portions which extendoutwardly and downwardly over an upper portion of a side portion of themain body preform assembly. In this configuration, one preferred form isthat each outer edge portion of the metal sheet has a bend at a locationspaced inwardly toward a center location of the metal sheet from itsouter edge portion, and an part of the outer edge portion issubstantially flat.

The ski made in accordance with the present invention comprises theupper cap section having a middle cap portion and side cap portions.This ski also has a main body portion comprising main body components ofthe ski.

The cap section has a middle cap portion and side cap portions. Itcomprises an elongate metal sheet which is predominantly metal and hasupper and lower surfaces and side edge portions. This elongate metalsheet comprises at least part of the middle cap portion.

Further, the cap section comprises two predominantly non-metal sidemembers having outer and inner surfaces and upper and lower edgeportions, with the upper edge portions being adjacent to the side edgeportions of the metal sheet at juncture locations.

There are two bonding strips, each located at a related one of thejuncture locations and joining a related one of the side members to anadjacent side portion of the metal sheet.

The metal sheet, the two side members and the two bonding strips arebonded together to form a sealed cap configuration.

Within the sealed cap configuration, there is the main longitudinallyextending body portion which comprises a core, a lower running surfacemember, and two side edge members which are bonded one to the other andalso to the cap section. Also, there is a lower metal sheet positionedbelow the core.

The core, metal sheet, side edge members and lower surface member arebonded together and also bonded to the cap section by a resin system,and the resin system is enclosed within the cap section, with lower endedges of the side members of the cap section forming seals at lower edgeportions of the main body portion.

Other features of the present invention will become apparent from thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a middle portion of the ski made inaccordance with the present invention;

FIG. 1A is an enlarged view of an upper right corner portion which iscircled in FIG. 1, showing a thermoplastic bonding film strip;

FIG. 2 is an isometric view showing the manufacturing lay-up to mold theski of the present invention;

FIG. 3 is an isometric view illustrating the lay-up to form thepre-assembly of the upper metal sheet, side members and bonding strips;

FIG. 4 is a cross-sectional view similar to FIG. 1A, showing a modifiedform of the pre-form assembly used in the present invention;

FIG. 5A is a cross-sectional view showing a modified pre-form assembly,with an edge portion of the upper metal sheet and a thermoplastic sidemember in an initial position in providing the pre-form;

FIG. 5B is a view similar to 5A but showing the pre-form after the heatis applied to form the pre-form assembly;

FIG. 6 is an isometric view illustrating the top surface of forwardportion of the ski, with a portion of the metal sheet being cut away anda component placed in the cutout for tuning the ski (e.g. dampening)and/or cosmetics;

FIG. 7 is a cross-sectional view of a third embodiment of the presentinvention, showing an edge portion of the ski of the third embodimentdrawn to an enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is believed that a better understanding of the present invention willbe obtained by first describing the structure of the ski as an endproduct, and then describing the method manufacturing the same.

The overall configuration of the ski is, or may be, conventional, sothat the ski has a tip portion, tail portion and intermediate portion,with the vertical thickness dimension of the ski decreasing from thecentral portion toward the end portions, and with the plan form of theski having the conventional side cut.

Within the broader scope of the present invention, the term “ski” is tobe interpreted to include snowboards or possibly other such products toincorporate the teachings of the present invention.

With reference to FIG. 1, which shows the ski at a center location incross-section, the ski 10 can be considered as having two mainstructural components, namely an upper cover section 12 (i.e. capportion or section 12), and a main body portion 13 which comprises acore section 14 and a bottom section 16.

The upper cap section 12 comprises an upper metal sheet 18, a pair ofside members 20, on opposite sides of the metal sheet 18, and twobonding strips 22 (shown more clearly in FIGS. 1A, 2 and 3) which jointhe upper metal sheet 18 to side members 20. In this particularembodiment, the bonding strips 22 are initially provided as separatestrips which are bonded to adjacent portions of the upper metal sheet 18and the side members 20. In an alternative embodiment, the bondingstrips are made as part of the side members 20 in their pre-formassembly configuration. (This will be described later herein withreference to FIGS. 5A and 5B.) In addition, there is a bonding layer 24extending beneath the metal sheet 18 and the side members 20 which joinsthe cover section 12 and main body portion 13.

The core section 14 is, in this preferred embodiment, made of a solidpiece of wood. The bottom section 16 comprises a lower metal sheet 26located immediately below the core section 14, and there are two steeledge members 28 located at lower side edges of the ski. Finally, thereis a lowermost plastic running surface 30 immediately below the lowermetal sheet 26, with outer side portions of the running surface 30 beingimmediately below the lower metal sheet 26 and below the inner flangeportions of the edge members 28.

It is to be understood that the cross-sectional configuration shown inFIG. 1 is substantially the same cross-sectional configurationthroughout the entire length of the ski, with the thickness dimensiondiminishing toward the end portion of the ski 10. But there could bevariations or somewhat different configurations at some portion orportions of the ski (e.g. the end portions of the ski).

The two metal sheets 18 and 26 can be high strength steel, stainlesssteel, Titanal®, other high strength aluminum alloys such as the 7000 or2000 series, titanium, or other high strength metals with a yieldstrength to modulus ratio in excess of 0.007. The metal sheets 18 and 26are desirably entirely made of metal, including metal alloys or metalalloys having an ingredient or ingredients that technically are not ametal, but within the broader scope it may be possible to formulate amaterial for the sheets 18 or 26 that would incorporate otheringredients, but still be predominantly metal.

To describe these elements in more detail, the upper metal sheet 18 is,in the preferred form, high strength steel having a thickness dimensionbetween about 0.008 to 0.020 inch, and in this embodiment about 0.015inch. Within this range, the thickness dimension could be 0.01 inch,0.012 inch, 0.124 inch, 0.016 inch, and 0.018. The sheet 18 has an uppersurface 32, a lower surface 34 and two side edges 36 (see FIG. 1A). Theupper metal sheet 18 is fully exposed to provide a desired bare metallicsurface which has benefits relative both to appearance of the ski andalso performance. This upper surface 32 can be provided with graphicsthereon.

Each of these side members 20 is predominantly non-metal and in thepreferred form is as an elongate, moderately flexible piece of plastic,such as Iso Sport's polyamide plastic ski top-sheet materials, having athickness dimension of possibly between 0.008 to 0.030 inch, and in thisembodiment about 0.024 inch. These could have other dimensional ranges,such as being as much as 0.01 inch, 0.012 inch, 0.014 inch, 0.016 inch,0.018 inch, 0.02 inch, 0.022 inch, 0.026 inch, and 0.028 inch. Also,quite possibly this could be a greater dimension such as 0.032 inch,0.034 inch or 0.036 inch, depending upon various other factors.

In the end configuration of the ski, each of these side members 20 hasan upper inner edge 38 (see FIG. 1A) and a lower outer edge 40 (see FIG.1). Each side member 20 extends the entire length of the ski andcomprises a main downwardly and outwardly sloping side portion 42, anupper side portion 44, and a lower side edge portion 46. The upper sideportion 44 has in cross-sectional configuration a curved configurationwhich terminates at the upper edge 38 of the side member 20, with thisupper edge 38 butting against the adjacent side edge 36 of the metalsheet 18 which in this embodiment is planar. The lower side portion 46of the side member 20 comprises a lower curved portion 48 and a loweroutwardly extending horizontal portion 50 which is located adjacent toan outer side edge portion of the lower metal sheet 26 and to itsrelated edge member 28.

Each of the aforementioned bonding strips 22, in the end configuration,is bonded to the outer lower side surface portion of the related edgeportion of the metal sheet 18 and also bonded to the lower surfaceportion of the upper part of its related side member 20. In thepreferred form, the thermoplastic bonding strip 22 is a flexiblethermoplastic film adhesive that is reinforced with fiberglass. As willbe described later herein, in the description of the manufacturingprocess, the two side members 20 and the bonding strips 22 each have thedesired characteristics for being formed first into a sub-assembly (asshown in FIG. 3) and then into the final configuration of the ski (asshown in FIGS. 1 and 2), this being described later herein, with regardto the manufacturing process.

The bonding layer 24 is, in this preferred embodiment, made offiberglass, and in the manufacturing process, a bonding resin permeatesthe fiberglass layer 24 to bond the metal sheet 18, the side members 20and the adhesive strips 22 to the core section 14. This fiberglass layer24 has, in the end configuration of the ski, a thickness dimensionbetween about 0.006 to 0.06 inch, and within that range could havethicknesses in the ranges of 0.01, 0.02, 0.03, 0.05, and a dimension ordimensions between any pair of these values.

The core section 14 is, or may be, of conventional design and is shapedto match the overall contour of the ski. Thus, it can be seen that incross-section the core section 14 has a trapezoidal configuration withthe side surfaces sloping downwardly with a steep outward slant which isbetween about 70° to 75° or 80° from the horizontal, and at the loweredge portions, has cut-outs 52 to accommodate the flange portions of theedge members 28.

To describe in more detail the components of the bottom section 16, thelower metal sheet 26 is made of high-strength steel (as is the uppermetal sheet 18) having a thickness dimension between about 0.008 to0.020 inch and in this embodiment about 0.012 inch. Depending uponvarious factors, this thickness of the lower metal sheet 26 could be (aswith the upper middle sheet 18) 0.01, 0.012, 0.014, 0.016, and 0.018inch. In this embodiment, the lower metal sheet 26 has its outer edgeportions raised slightly as at 54, the raised portions being formed by asmall connecting step portion or joggle 56, this being done toaccommodate the inner flanges 57 of the steel edges 28. Alternatively,the joggled portions 54 could be eliminated and the outer edges of thesteel sheet 26 could terminate at the inner edges of the flanges. Thiswill be described later herein with reference to FIG. 7.

The steel edges 28 are, or may be, of conventional design, and as showherein, there is the main outer rectangular edge portion 58 and, asindicated previously, an inwardly extending flange portion 57 by whichthe steel edge members 28 are mounted.

Finally, there is the aforementioned plastic running surface 30 whichis, or may be, of conventional design, bonded to the bottom surface ofthe lower metal sheet 26. This plastic running surface extends betweenthe inwardly facing surfaces of the outer edge portions 58 of the edgemembers 28.

To describe now the manufacturing process of the present invention,reference is initially made to FIG. 3, which shows the layup of the cappre-form assembly, designated 59. The manufacturing process of thisfirst embodiment is essentially a two-step operation. The first step isto form a cap pre-assembly 59 (or pre-form assembly 59) which is made upof three elements which, in the final configuration of the ski, are theupper metal sheet 18, the two side members 20, and the two bondingstrips 22. The bonding strips 22 may be reinforced with woven ornon-woven fabric as two separate pieces or a pre impregnated material.For clarity in describing the manufacturing process, these threeelements, 18, 20 and 22, will, in the description of the manufacturingprocess, be given “a” suffixes, so that these will be designated 18 a,20 a and 22 a, respectively, and the other components or elementsrelated to this pre-assembly will also have “a” suffixes. In FIG. 3, thelateral edges 60 a of the side members 20 a are shown as having astraight-line configuration. These lines 60 a can also have a curvedconfiguration so as to follow the contours of the outer edges 36 a ofthe top metal sheet portion 18 a. Since these components 18 a, 20 a, and22 a form the cap pre-assembly which becomes the cap section 12 in thefinal ski configuration, the cap pre-assembly shall be designated 12 a.

To form this cap pre-assembly 12 a, the metal sheet 18 a is laid on aflat surface, and the two side members 20 a, in the form of flat stripsof plastic material, are laid on opposite sides of the side edges 36 aof the metal sheet 18 a, so that the edges 38 a of the two side members20 a abut against the side edges 36 a of the metal sheet 18 a. Then thetwo bonding strips 22 a are each laid over a related juncture line ofthe abutting edges 36 a-38 a, so that each of the bonding strips 22 ahas inner and outer bonding sections 61 a and 62 a.

Then heat is applied to the bonding strips 22 a in a conventionalmanner, such as by pressing a heated surface of a platen against the twobonding strips 22 a. This film adhesive can be a thermoplastic materialso that it is flexible in the subassembly and has limited flow (i.e.controlled flow) during the subassembly manufacturing to prevent flow ofadhesive onto the metal top sheet. This bonding strip 22 a has a veryfast process time of typically one to three minutes since no “cure” isrequired like a thermoset adhesive. The bonding strip 22 a remainssubstantially solid during the final assembly. Also, the plasticsidewall members 20 and bonding strips 22, with or withoutreinforcement, are able to readily conform to the molded ski shape.

Further, the thermoplastic material can be reinforced with higher melttemperature or higher modulus layer of a woven or unidirectionalreinforcing fabric, such as fiberglass, polyester or even cotton. Theadditional reinforcement can also act to promote bonding adhesion of thepre-form cap assembly 12 a during the final ski assembly. It alsoprevents the material of the side members 20 from pulling apart from themetal sheet 18 during mold closing and also during the period of finalassembly cure pressure and temperature.

Further, it will be noted, with reference to FIG. 2, that the lowerouter portion of each side member 20 a are sized so that the lateraledges 65 a protrude beyond the molding surface of the ski footprint, asindicated at 62 a (see FIG. 2), so as to force all excess resin fromfinal assembly away from the ski. This is in contrast to a net-formedmetal cap where the adhesive is able to run up along the side of theski.

To describe the second step in the manufacturing process of this firstembodiment (i.e., molding of the final assembly to bond all of thecomponents together), reference is made to FIG. 2.

As shown in FIG. 1, there is a mold base 64 and a mold lid 66, withthese two mold components 64 and 66 having mold surface contourscorresponding to the configuration of the final ski. Initially, theplastic running surface 38 a and the two edge members 28 a arepositioned in the mold base. As is commonly accomplished in the priorart, the two edge members 28 a can be initially pre-bonded to therunning surface 30 a and then placed in the mold base 64.

Next, an adhesive layer is placed on top of the running surface 30 a andupper surface portions of the edge members 28 a, and the lower metalsheet 26 a is put in place. Alternatively, instead of applying theadhesive directly, the adhesive can be formed in an impregnated layer offabric, fiberglass or some other material (e.g., Kevlar, woven ornon-woven polyester, etc.) and this adhesive layer placed on top of therunning layer 30 a and the upper surface portions of the edge members 28a.

Next, an adhesive material is applied to the upper surface of the lowermetal plate 26 a and then the core member 14 a is put in place. Again,it may be possible to place a layer of fabric between the metal sheet 26a and the core member 14 a or have the fabric be adhesive impregnated,or with the adhesive being applied to the layer of fiber or fabric.

With the core member 14 a in place, the aforementioned bonding layer 24a (e.g., a fiberglass bonding layer 24) is placed over the core member14 a so that the fabric has an upper portion 68 a on top of the coremember 14 a, two side portions 70 a that extend downwardly along thesides of the member 14 a, and finally two outwardly and laterallyextending portions 72 a which extend beyond the edge members 20 a andover an adjacent surface portion of the mold base 64. A liquid adhesivematerial could be applied to this bonding layer 24 a, or (as mentionedearlier) this layer 24 a could be an adhesive impregnated layer.

As a final step, the cap pre-form assembly 12 a (made up of the metalsheet 18 a, the side members 20 a, and the bonding strips 22 a), isplaced as a unit 12 a on top of the bonding sheet 24 a. The outerportions (comprising the side members 20 a) of this sub-assembly 12 aare manually moved downwardly over the sides of the other componentswhich are already in place in the mold base 64, and then the mold lid 66is moved downwardly to press the components into their proper position.During the molding process, if there is an outward flow of liquidmaterial (e.g. resin or other bonding agent material), this flow will beoutwardly beneath the outer layer portions 72 a and 73 a.

After the molding process is completed and after the bonded ski assemblyis removed from the mold, then the outer edge portions formed by themembers 72 a and 73 a are ground off.

To discuss further some facets of the method of the present invention,the temperature at which the cap pre-form assembly 12 a is bonded issufficiently high so that each bonding strip 22 becomes “sticky enough”so that it would bond to both of the components (i.e. the upper metalsheet 18 a and also the side member 20 a). The temperature at which thethermal plastic bonding strip 22 becomes sufficiently “sticky” so as tobe able to bond the components 18 a, 20 a and 22 a to be bonded ishigher than the temperature which the entire pre-form assembly shown inFIG. 2 is subjected during the final molding process.

Also, it is to be understood that while the thermoplastic material isdesirable for being used in the bonding strip 22, it would be possibleto utilize a thermoset plastic (or some other material) which would havean adhesive surface that would adhere to both the metal sheet 18 a andthe side member 20 a. Present inquiries by the applicants have notidentified an adhesive material which they believe would be adequate forthis particular application, but on the assumption that such adhesivematerials are available and are found reliable, these could beconsidered for use as the bonding strip 22.

Also, the thermoplastic material which comprises the bonding strip 22should have a sufficiently high viscosity at the bonding temperature sothat it would not become sufficiently liquid to leak through the joint36/38.

There are various advantages in using the combination of the upper metalsheet 18 and the side members 20 made of a non-metal material such as aplastic material. Functionally, as indicated previously, the upper metalsheet 18 clearly serves as a structural member. It has a highstrength-to-weight ratio and it also adds to the torsional resistance ofthe ski. Also, this particular arrangement of having the outer edges ofthe metal sheet 18 terminate at a location spaced from the lower edgebenefits in the manufacturing process. It is more difficult to maintainthe tolerances of the edge of the metal sheet within close limits,especially when there is a bend in the metal. By using the plasticsidewall member 22, the tolerance problem is in large part removed.

Further, there is another benefit in using the plastic material orsimilar material as the side members 20. If there is an impact on theski (e.g. the lower steel edge 28 striking a rock), the plastic sidewall20 is able to absorb the shock and not delaminate from the wood core 14.

It should also be noted that the formation of the pre-form assembly 12 abeing formed first and then being placed on the final pre-form assembly,is that the bonded cap pre-form assembly 12 a functions as aliquid-tight assembly which, in the final assembly of FIG. 2,substantially encloses the rest of the components and leaves as an exitarea the two seams that are formed at the very lower edge portions ofthe final pre-assembly at the edge locations 50 of the side members 22.Also, as can be seen in the pre-form of FIG. 2, the resin (or possiblyother liquid material, if any) which is extruded out of the pre-formassembly necessarily travels underneath the outer edge portion 73 a ofthe side member 20 so that it does not come in contact with the ski.

A second embodiment of the present invention is shown in FIG. 4.Components of the second embodiment which are similar to components ofthe first embodiment will be given like numerical designations with a“b” suffix distinguishing those of the second embodiment. As shown inFIG. 4, there is the upper metal sheet 18 b and the two side members 20b. The upper metal sheet 18 b has its edge portion formed in a downwardcurve as at 74 so that there is a juncture line 76 with the side edge 20b which has at that juncture location a planar configuration. Thisarrangement of the upper metal, sheet gives the ski a greater torsionalresistance. This outer curved edge portion 74 can be formed byhydro-forming or other metal die forming operations.

A third embodiment is illustrated in FIGS. 5A and 5B. Components of thisthird embodiment which are the same as or similar to components of theearlier two embodiments will be given like numerical designations with a“c” suffix distinguishing those of the third embodiment. The upper metalsheet 18 c is the same as the sheet 18 but the side member 20 c differs.Each side member 20 c is made as a thermoplastic layer with an innerportion 78 of this thermoplastic layer being beneath an outer edgeportion 80 of the metal sheet 18 c in the cap pre-form assembly 12 a. Asthe heat is applied, the metal plate portion 80 becomes depressed intothe inner portion 78 of the softened thermoplastic layer 20 c to squeezedown the edge portion 78. At the completion of the formation of thepre-form assembly the upper surface 82 of the metal sheet 18 c lies inthe same plane as the main upper surface portion 84 of the side member20 c. Then the pre-form assembly in each of these modifications (FIG. 4,and FIGS. 5A and 5B) are molded into the final ski configuration asdescribed previously.

To describe a modified form of the present invention, reference is madeto FIG. 6 which shows a front end tip portion of the ski at 86. Forcosmetic reasons or to tune the dynamic performance (e.g. vibrationdampening), it may be desirable to provide a cut out in the top metalsheet 18. In FIG. 6 there is a cut out at 88 in the ski tip portion ofthe upper metal sheet 18. The region of the cut out 88 (shown herein asa circular cut out) could be patched with a piece of the same materialas is used to making the side member 20 (this material being indicatedat 90) along with a bonding layer made of the same material as thebonding strip 22. The edge portion of this bonding layer 90 is shown asan edge portion 86 surrounding the cut out 82, it being understood thatthis adhesive 86 would extend also beneath the patched portion 90.

A fourth embodiment of the present invention is illustrated in FIG. 7.Components of this fourth embodiment which are similar to (or the sameas) components of the prior embodiments will be given like numericaldesignations, with a “d” distinguishing those of the fourth embodiment.There are three main distinctions between the fourth embodiment and thefirst embodiment. The first is that configuration of the components atthe upper outer edge portion of the final pre-form and the finished skiis modified from what is shown in FIG. 1. The second is that the bondingstrip 22 d is extended so that it extends entirely down the inside ofits related sidewall 20 d and all the way to the outer edge portion ofthe pre-form assembly, so that it would be extending between the outeredge portion 73 a and 72 a, as shown in FIG. 2. The third is the lowermetal sheet 26 d has its outside edge terminate adjacent to the inneredge 57 d of the edge member 28 d.

Let us turn our attention now to the first item listed in the paragraphimmediately above. It will be noted that the upper metal sheet member 18d is formed with a longitudinally aligned bend at 94 d adjacent to anouter edge portion 95 d of the middle planar portion of the metal sheet18 d. Then immediately outwardly of the rounded portion 94 d, there is aflat outer sheet metal portion 96 d which terminates at the juncturelocation 36 d/38 d. Then from the juncture location 36 d/38 d, the sidemember 22 d begins as a planar portion 98 d which leads from its edge 38d and transitions into a longitudinal curved portion 100 d, which inturn leads into a downwardly extending portion 102 d. Then the lower endof the planar portion 102 d leads into the outer edge portion 46 d whichis substantially the same as the portion 46 in the first embodiment.

The second item in this fourth embodiment that differs from the firstembodiment is, as indicated above, that the bonding strip 22 d extendsall the way from the beneath the outer edge portion of the metal sheet18 d all the way down along the side of the ski, and then extendslaterally outwardly as show in FIG. 7. Thus, the bonding strip 22 dsimply follows the contour of the metal strip portions 95 d, 94 d, and96 d, and from there follows the contours 98 d, 100 d, 102 d, and 46 dof the side member 20 d.

As indicated previously, the third item in this fourth embodiment thatdiffers from the first embodiment in that the lower metal sheet 26 dterminates at a further inward location than in the first embodiment.More specifically, the outer side edge 106 d of each side of the lowersheet 26 d terminates adjacent to the inwardly facing edge 108 d of theflange 57 d.

Since the flange 57 d generally has a greater thickness dimension thanthe thickness dimension of the lower metal sheet 26 d, there is in thepreferred embodiment provided a filler material 110 d immediately abovethe metal sheet 26 d so that the upper surface 112 d of the flange 57 dis in the same plane as the upper surface 114 d of the filler material110 d. This layer of filler material 110 d could be a porous, woven ornon-woven plastic layer impregnated with resin. This could bepre-pregged, in which case it would soften and bond, or at the time ofmanufacture it could be coated with a copper layer which would bebonding.

Also, the two flanges 57 d of the steel edges 28 d would be bonded bythe upper surface 112 d to the wood core. This could be done by applyinga proper adhesive or bonding agent at the time of being placed in themold. Also, it is possible to place other material such as a rubber orfiberglass layer between the flange 57 of each steel end 28 and the woodcore 14.

The method of manufacture of the present invention would be modifiedfrom that of the first embodiment to some extent to make the ski shownin FIG. 7. More specifically, the initial pre-form operation describedabove with reference to FIG. 3 would be modified so this would, become atwo-step operation.

The first step would be to form the pre-form substantially the same asdescribed above with reference to FIG. 3. Thus, the metal sheet 18 d,the side members 20 d, and the two bonding strips 22 d would beassembled substantially the same as in FIG. 3. However, with the bondingstrips 22 d extending further outwardly, the outer edge of the bondingstrips 22 d would reach substantially out to the outside edges 63 a ofthe edge members 20 a, as shown in FIG. 3.

After the pre-form flat layup is subjected to heat and pressure by theplaten, then the bonded assembly is moved to perform a hydroformingoperation where an upper molding member would be moved downwardly toengage the upper surface of the bonded pre-assembly and thus deform theouter edge portions of the metal sheet 18 d to form the bend at 94 d andalso the outer planar section 96 d. The side members 20 d would also bedeformed downwardly. In a preferred form, the angle of the planarportion 96 d would also make an angle of about one-third of a rightangle with the main horizontal portion of the metal sheet 18 d. Then thebonded pre-form, with the bends made in the outside metal sheetportions, is moved over to the final assembly, and in the final moldingoperation, the outwardly extending side portions 20 d would be moveddownwardly to press against the sidewalls of the core 14 d.

In other respects, the manufacturing operation to make the ski of thefourth embodiment would be substantially the same as described above,and in the final molding operation the finished ski product is formed.

It has been found that the hydroforming step described above could beaccomplished more effectively by placing a layer of nylon aboutone-eighth inch thick between the softer hydroforming material and theupper surface of the pre-assembly. This allows proper forming, and wouldprevent possible rupturing of the joints of the metal sheet 18 d and theside members 20 d.

A further aspect of the present invention is that the bonding strips 22d could be formed in a particular manner to enhance its functions. Morespecifically, the bonding strip 22/22 d of both the first and secondembodiments could be made with an outer surface (i.e. the surface thatfaces the side members 20 and the metal sheet 18) is made of a materialthat bonds well to both steel and polyamide (the material with which theside members 20 are made). This layer could be, for example, about 0.01inch. Then there would be an inner surface thermal plastic layer thatbonds well to epoxy resin systems that are used in the final molding ofthe ski. Such a poly resin system is available from Sarna (a Swisscompany). This also could be made with a thickness dimension of 0.01inch or thinner. The middle portion of the material forming the bondingstrip 22/22 d could be made of a thermoplastic material that isdescribed above.

Another feature of the present invention is that it enables cosmetics tobe conveniently applied to the side portions of the ski. For example,the middle portion of the bonding strip 22/22 d, as describedimmediately above, could be provided with cosmetics, and it can be, forexample, a decorative pattern made of woven fiberglass, woven fiberglasswith metallic copings, or fabric with printing, etc. In this instance,the side members 20/20 d would be substantially transparent. Anotheroption is that the polyamide sidewall could be back-printed byconventional techniques. Also, the decorative pattern could besublimated into the body of the sidewall 20/22 in accordance withtechniques that are well known in the art.

It is obvious that various modifications could be made to the presentinvention without departing from the basic teachings thereof.

1. A method of manufacturing a ski having a front to rear longitudinalaxis, front and rear end portions, upper and lower surface portions, andside surface portions, said ski further comprising a main longitudinallyextending body portion comprising main body components of the ski and alongitudinally extending cap portion at the upper and side surfaceportions of the ski, said method comprising: a) making a cap preformsection having a middle cap preform portion and side cap preformportions, and comprising: i. an elongate metal sheet which ispredominantly metal and has upper and lower surfaces and side edgeportions; ii. two predominantly non-metal side members having upper andlower surfaces and inner and outer edge portions, with the inner edgeportions being adjacent to the side edge portions of the metal sheet atjuncture locations; iii. two bonding portions, each being located at arelated one of the juncture locations and joining a related one of theside members to an adjacent side portion of the metal sheet; b)positioning preform main body components corresponding to the main bodycomponents of the ski at a molding location as a main body preformassembly with upper, lower and side surfaces, and lower side edgeportions; c) positioning the cap preform section over the main bodypreform assembly so that the metal sheet is located over the uppersurface of the main body preform assembly; d) pressing the middleportion of the cap preform section downwardly against the top surface ofthe main body preform assembly and pressing the cap preform section sideportions against the side surfaces of the main body preform assembly toform a bonding assembly and applying heat to cause the cap preformsection and the main body preform assembly to become bonded into a skistructure.
 2. The method as recited in claim 1, wherein an upper moldsection is pressed downwardly to press the cap preform assemblydownwardly against the main body preform assembly.
 3. The method asrecited in claim 2, wherein in the bonding assembly outer edge portionsof the cap preform section extend outwardly beneath lower edge portionsof the upper mold section form edge seals to contain liquid material inthe main body preform assembly.
 4. The method as recited in claim 1,wherein a lower metal sheet which is predominantly made of metal is acomponent of the main body preform assembly.
 5. The method as recited inclaim 4, wherein said main body preform assembly comprises a core, andthe lower metal sheet is located beneath said core.
 6. The method asrecited in claim 5, wherein said main body preform assembly furthercomprises lower metal side edge members having inwardly extendingflanges with inner edge surfaces which are positioned adjacent to outeredge surfaces of the lower metal sheet.
 7. The method as recited inclaim 4, wherein said main body preform assembly further comprises lowermetal side edge members having inwardly extending flange portions, andouter edge portions of the lower metal sheet and the inwardly extendingflange portions are in overlapping relationship.
 8. The method asrecited in claim 4, wherein the outer edge portions of the cap preformassembly extend beyond lower side edge locations of the ski which isformed, said method further comprising trimming back the outer edgeportions of the cap preform assembly to form the ski.
 9. The method asrecited in claim 1, wherein each of said bonding portions comprise anend edge portion of a related one of the side members, and said sidemembers are made of a thermoplastic material, and an adjacent edgeportion of the metal sheet is pressed against the edge portion itsrelated side member so as to form a bond between side member and saidmetal sheet.
 10. The method as recited in claim 1, wherein each of saidtwo bonding portions comprises a bonding strip having an upper bondingsurface, said cap preform section being made by providing a cap preformassembly comprising said metal sheet, said side members and said bondingstrip in overlapping relationship and applying heat to bond the bondingstrips to the metal sheet and the side members to form the cap preformsection.
 11. The method as recited in claim 10, wherein each of saidbonding strips is a thermoplastic material, and the bonding assembly issubjected to pressure and heat at a sufficiently high temperature tocause each bonding strip to become adhesive, and upon cooling, forms abond with the adjacent side member and the metal sheet.
 12. The methodas recited in claim 11, wherein said metal sheet and the two sidemembers meet in edge to edge of abutting relationship, and each of saidthermoplastic bonding strips is heated to a sufficiently high level tocreate bonding, with each thermoplastic strip having a sufficiently highviscosity at the bonding temperature so that leakage does not occurthrough a joint formed by the metal sheet and the side member.
 13. Themethod as recited in claim 9, wherein each bonding strip extendsdownwardly along side surface portions of its related side member to itsrelated lower side edge portion of the main body preform assembly. 14.The method as recited in claim 9, wherein each of said bonding stripshas an outer surface portion having a material which readily bonds tometal material forming said upper metal sheet and also to plasticmaterial forming its related side member, and an inner surface materialparticularly adapted to bond to a resin system which is incorporated ina main body preform assembly.
 15. The method as recited in claim 1,wherein the metal sheet has two side edge surfaces, each of which is inabutting relationship against an adjacent side edge portion of the sidemember.
 16. The method as recited in claim 15, wherein said upper metalsheet is entirely flat, and is positioned at an upper top surface ofsaid ski.
 17. The method as recited in claim 15, wherein said uppermetal sheet has side edge portions which extend outwardly and downwardlyover an upper portion of a side portion of said main body preformassembly.
 18. The method as recited in claim 17, wherein each outer edgeportion of the metal sheet has a bend at a location spaced inwardlytoward a center location of the metal sheet from its outer edge portion,and an outer part of the outer edge portion is substantially flat. 19.The method as recited in claim 17, wherein after the metal sheet isbonded to the two side members, the resulting cap preform section issubjected to a hydro-forming operation to bend outer portions of theupper metal sheet downwardly, after which the cap preform section isplaced onto the main body preform assembly to be pressed downwardlyagainst the main body preform assembly.
 20. A ski made in accordancewith the method of claim
 1. 21. A ski having a front to rearlongitudinal axis, upper and lower surface portions, and side surfaceportions, said ski comprising: a) a cap section having a middle capportion and side cap portions, said section further comprising: i. anelongate metal sheet which is predominantly metal and has upper andlower surfaces and side edge portions, and comprises at least part ofsaid middle cap portion; ii. two predominantly non-metal side membershaving outer and inner surfaces and upper and lower edge portions, withthe upper edge portions being adjacent to the side edge portions of themetal sheet at juncture locations; iii. two bonding strips, each beinglocated at a related one of the juncture locations and joining a relatedone of said side members to an adjacent side portion of the metal sheet;iv. said metal sheet, two side members and two bonding strips beingbonded together to form a sealed cap configuration; b) a mainlongitudinally extending body portion which comprises a core, a lowersurface member, a lower steel sheet between said core and said lowersurface member, and two side edge members which are side members, saidcore, lower surface member, lower metal sheet and two side members beingbonded to one another and also being bonded to the cap section by aresin system; c) said ski being characterized in that said main bodysection with said resin system is enclosed within the cap section, withlower edge portions of the side members of the cap section forming sealsat lower edge portions of the main body portion.